@robert: are you using webpack loader? We tracked this bug to an elm-webpack-loader behaviour. here is the issue. https://github.com/rtfeldman/elm-webpack-loader/issues/60
For now, the workaround I am using is to import Json.Decode in my Ports file. On Monday, 8 August 2016 22:30:16 UTC+5:30, Robert Walter wrote: > > It doesn't seem like it is tracked. I ran into the same(?) issue in my > project and I tried to create a SSCCE so I could file an issue, but the > thing is I cannot get a SSCCE to fail like my project. My projec tis in the > middle of a bigger refactoring, which makes it particularly hard for me to > boil it down to a SSCCE. > > @Aditya: can you share some more information? In my case, my port module > is called "Ports". If I do not have an import statement for Json.Decode, I > run into the very error you mentioned at the beginning. Adding the import > statement fixes the issue. > > > > On Monday, August 1, 2016 at 6:01:09 AM UTC+2, Duane Johnson wrote: >> >> Cool bug find :) Is it tracked on >> https://github.com/elm-lang/elm-compiler/issues ? >> >> On Sun, Jul 31, 2016 at 3:01 AM, Aditya Vishwakarma <blackle...@gmail.com >> > wrote: >> >>> Hi >>> >>> So I dug deeper into this issue. turns out that the JS code for my port >>> module was being emitted before the JS of Json.Decode module. >>> >>> After some research, I found that if the project's port module has: >>> >>> - Name beginning with a letter before J, and >>> - does not have a declared dependency on Json.Decode >>> >>> Then the elm compiler will emit the port module code before >>> `Json.Decode` which causes all decoders to be `Undefined`. This results in >>> all user defined incoming ports to stop throw exceptions. >>> >>> SSCCE: https://github.com/adityav/elm-ports-issue >>> >>> >>> On Friday, 29 July 2016 02:27:41 UTC+5:30, Aditya Vishwakarma wrote: >>>> >>>> Hi >>>> >>>> I am getting Uncaught TypeError: Cannot read property 'tag' of >>>> undefined in a sample code I built to tryout elm. The error happen when I >>>> send JSON data across the elm port from JS side. >>>> >>>> Port defn: >>>> https://github.com/adityav/elm-reddit-listing/blob/master/src/AppPorts.elm#L14 >>>> JS call which causes this issue: >>>> https://github.com/adityav/elm-reddit-listing/blob/master/src/index.js#L36 >>>> git repo: https://github.com/adityav/elm-reddit-listing >>>> >>>> To run. Simply do >>>> npm install && elm package install >>>> npm start >>>> >>>> and open http://localhost:8080/. A listing of /r/elm should show up >>>> when the app works. >>>> >>>> A screenshot of the exact location where the error occurs: >>>> >>>> >>>> <https://lh3.googleusercontent.com/-5aH4m9n6gEw/V5pu35oQsEI/AAAAAAAAEbw/QKXJrtSqgcA6-Dfe_BVsDOYPpn9BHl6MACLcB/s1600/Screen%2BShot%2B2016-07-29%2Bat%2B1.39.20%2BAM.png> >>>> >>>> People on slack recommended me to remove elm-stuff/build-artifacts and >>>> try again. It didn't work so I removed node_modules and elm-stuff >>>> directories and reinstalled the whole thing. Didn't work as well. >>>> The code was working before I decided to clean it up a little to show >>>> to my teammates. Stopped working the moment I shared the github link with >>>> them. :| >>>> >>>> anyone got any ideas on this? >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Elm Discuss" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to elm-discuss...@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
